fix: add a maxOutputLength option to zlib inflate

panva · Mar 7, 2024 · 02a6579 · 02a6579
1 parent d1be83f
commit 02a6579
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Showing 4 changed files with 28 additions and 2 deletions.
diff --git a/docs/README.md b/docs/README.md
@@ -1494,6 +1494,8 @@ operation.
     Count) Header Parameter value. The PBKDF2 iteration count defines the algorithm's computational
     expense.
     **Default:** '10000'
+  - `inflateRawSyncLimit`: `number` Limits compressed JWE plaintext output size.
+    **Default:** '250000'
   - `complete`: `<boolean>` When true returns an object with the parsed headers, verified
     AAD, the content encryption key, the key that was used to unwrap or derive the content
     encryption key, and cleartext instead of only the cleartext.

diff --git a/lib/jwe/decrypt.js b/lib/jwe/decrypt.js
@@ -52,7 +52,7 @@ const validateAlgorithms = (algorithms, option) => {
 /*
  * @public
  */
-const jweDecrypt = (skipValidateHeaders, serialization, jwe, key, { crit = [], complete = false, keyManagementAlgorithms, contentEncryptionAlgorithms, maxPBES2Count = 10000 } = {}) => {
+const jweDecrypt = (skipValidateHeaders, serialization, jwe, key, { crit = [], complete = false, keyManagementAlgorithms, contentEncryptionAlgorithms, maxPBES2Count = 10000, inflateRawSyncLimit = 250000 } = {}) => {
   key = getKey(key, true)
 
   keyManagementAlgorithms = validateAlgorithms(keyManagementAlgorithms, 'keyManagementAlgorithms')
@@ -189,7 +189,7 @@ const jweDecrypt = (skipValidateHeaders, serialization, jwe, key, { crit = [], c
     let cleartext = decrypt(enc, cek, base64url.decodeToBuffer(ciphertext), { iv, tag, aad: adata })
 
     if (opts.zip) {
-      cleartext = inflateRawSync(cleartext)
+      cleartext = inflateRawSync(cleartext, { maxOutputLength: inflateRawSyncLimit })
     }
 
     if (complete) {

diff --git a/test/jwe/sanity.test.js b/test/jwe/sanity.test.js
@@ -1,4 +1,5 @@
 const test = require('ava')
+const crypto = require('crypto')
 
 const base64url = require('../../lib/help/base64url')
 const { JWKS, JWK: { generateSync }, JWE, errors } = require('../..')
@@ -616,3 +617,25 @@ if (!('electron' in process.versions)) {
     }, { instanceOf: errors.JWEInvalid, message: 'JOSE Header "p2c" (PBES2 Count) out is of acceptable bounds' })
   })
 }
+
+test('Compressed JWE output length limit', t => {
+  const k = generateSync('oct', 256)
+  {
+    const jwe = JWE.encrypt(crypto.randomBytes(250000), k, { alg: 'dir', enc: 'A128CBC-HS256', zip: 'DEF' })
+    t.notThrows(() => {
+      JWE.decrypt(jwe, k)
+    })
+  }
+  {
+    const jwe = JWE.encrypt(crypto.randomBytes(250000 + 1), k, { alg: 'dir', enc: 'A128CBC-HS256', zip: 'DEF' })
+    t.throws(() => {
+      JWE.decrypt(jwe, k)
+    })
+  }
+  {
+    const jwe = JWE.encrypt(crypto.randomBytes(1001), k, { alg: 'dir', enc: 'A128CBC-HS256', zip: 'DEF' })
+    t.throws(() => {
+      JWE.decrypt(jwe, k, { inflateRawSyncLimit: 1000 })
+    })
+  }
+})
diff --git a/types/index.d.ts b/types/index.d.ts
@@ -402,6 +402,7 @@ export namespace JWE {
     contentEncryptionAlgorithms?: string[];
     keyManagementAlgorithms?: string[];
     maxPBES2Count?: number;
+    inflateRawSyncLimit?: number;
   }
 
   interface completeDecrypt {